This proposal is designed to expand the base of knowledge related to the psychophysical, clinical, and psychophysiological variables that affect the reaction to laboratory and pathological pain. The aims for the coming year are: 1) continuation of a long-range study comparing migraine headache sufferers to normals on a number of dimensions including psychophysical evaluations of pain and general psychophysiological responsivity; 2) addition of a population of arthritic subjects for comparison to both normals and migrainous subjects along the same dimensions; 3) continuation of research in the utilization of psychophysical evaluation of pain and pain descriptors for use as pain response measures; 4) evaluation of the effects of various treatments on the course of the chronic pain conditions of the migrainous and arthritic subjects.